refactor: simplify router configuration and handler setup

- Move JWT middleware creation to shared function
- Simplify library route registration
- Add bulk-add-books endpoint to collections
- Clean up duplicate handler setup code
- Improve route organization and maintainability

internal/router/router.go

@@ -108,6 +108,11 @@ func RegisterRoutes(cfg *Config) {
 	rateLimiter := ratelimit.NewRateLimiter(rateLimiterConfig)
 	rateLimitMiddleware := ratelimit.RateLimiterMiddleware(rateLimiter)
 
+	// Register core application routes (collections, devices, media, etc.) - ONCE
+	jwtMiddleware := createJWTMiddleware(cfg)
+	protected := e.Group("/api", jwtMiddleware)
+	handlers.SetupRoutes(protected, cfg.Queries, cfg.ConnManager)
+
 	// Register route groups
 	registerAuthRoutes(cfg, rateLimitMiddleware)
 	registerLibraryRoutes(cfg)